I understand that no Operating System is 100% safe. Although this backdoor is likely only affects certain Linux desktop users, particularly those running unstable Debian or testing builds of Fedora (like versions 40 or 41), **Could this be a sign that antivirus software should be more widely used on Linux desktops? ** ( I know this time is a zero-day attack)
What if, malicious code like this isn’t discovered until after it’s released to the public? For example, imagine it was included in the initial release of Fedora 40 in April. What if other malware is already widespread and affects more than just SSH, unlike this specific case?
My point is,
- Many people believe that Linux desktops don’t require antivirus software.
- Antivirus can at least stop malware once it’s discovered.
- Open-source software is protected by many parties, but a backdoor like this one, which reportedly took 2 years to plan and execute, raises my concern about being more cautious when choosing project code maintainers.
- Linux desktops will likely be targeted by more attacks as they become more popular.
IMO, antivirus does not save stupid people(who blindly disable antivirus // grant root permission) but it does save some lazy people.
OS rely heavily on users practicing caution and up-to-date(both knowledge and the system). While many users don’t follow tech news, they could unknowingly be running (this/any) malware without ever knowing. They might also neglect system updates, despite recommendations from distro maintainers.
This is where antivirus software can be useful. In such cases, users might be somewhat protected once the backdoor signature is added to the antivirus database.
Thankfully, the Linux community and Andres Freund responded quickly to this incident.
Anti-viruses are a scam and always have been. They aren’t much more than security theater and box ticking. Don’t get into the mindset that you can outsourse security to a single product. Security is something that happens in depth. The more intrusive av software can itself become an attack vector as it often runs with lots of privileges.
Distros operate with webs of trust and cryptographically signed packages. Your distro installer verifies the integrity of the package. There is no need to check a third party signature database. It adds no value. Even well audited software could contain hidden vulnerabilities so increasingly we are running software with less capabilities via systemd, flatpak/brwrap or in containers. The environment is very different to the origins of av software on Window 9x where people would download random unsigned executables to a system with no privilege restrictions.
There are lots of challenge for the FOSS community. We love features and freedoms and those features and freedoms sometimes make security more complicated. We need to show more restraint packaging software like ssh and not add so many patches and additional dependencies. We also need to show more restraint in the typical rust, go or javascript project where adding dependencies is so easy we end up sometimes including hundreds of them for stupid crap like coloured messages or being able to handle a dozen config file formats. I don’t care about your garbage collection or advanced compile time checks, if you include hundreds of crates from other developers you are no better than npm and I would put more faith in a 20 year old c library.
And more, it’s known that av can increase sloppy behavior regarding security in people that does not know about security, making them feel safe and, therefore, clicking anywhere and installing anything
Av does increase the risk of being infected for most people
The way this xz backdoor was treated is good enough!
- Identify
- Announce
- Evaluate
- Rollback
Always with good version control and cryptographic keys to sign the packages
An antivirus wouldn’t protect against the xz exploit. Imagine it did pull down the database of hashes and found a malicious xz binary, what is it going to do?
It can’t quarantine it, because that would break programs. It could update it, but shouldn’t your package manager be the one in charge of that? So the best it can do is notify you of the exploit… Which also feels like a thing the package manager should be doing.
I think instead of an antivirus, we should have a stricter permissions model. Certain applications can identity locations as “private” which blocks untrusted applications. So a random file you downloaded won’t be able to read your browser cookie jar or Discord session.
Random files you download from the internet should be executed in an unprivileged context which requires a “do you want this application to have access to this?” prompt whenever it does something sketchy.
Interestingly, afaik, Valve already runs Windows games in a secure container when using Proton. Fun fact.
I’d add that if one of the basic libraries is compromised, you can’t trust the anti-virus or really any other program on that system.
Yep, the antivirus might need a compression library to manage its database. :P
The xz issue might not directly affect an anti-virus, so maybe in this specific case, it would work fine. But it wouldn’t be hard to come up with another library that would make the anti-virus moot. And even in the xz situation, doesn’t it affect systemd?
All bets are off when you can no longer trust low level software like this.
https://cyberplace.social/@GossiTheDog/112194735806991939
"4 days since XZ backdoor became public knowledge and most major Linux AV and EDR security vendors still have zero detections… they haven’t even set the static file hashes as malicious.
Can’t wait for all the vendor blogs in a week saying they fully protect against the threat. 👍"
The answer to your question: no.
Unless they’re running LFS, I don’t see the point. By the time the antivirus database is updated, surely an update will be available in the package repo?
The Linux ecosystem is built around package repos rather than manually installed software, so antivirus makes even less sense on Linux than it does on Windows. If there’s malware it’ll get removed from the repo as soon as it’s detected.
I generally agree, but I will point out there are more ways to get packages than a repo - sure most things come from there, but plenty of things are provided as standalone installers (e.g., .deb packages). Having something that can scan that random .deb you need to do that one thing could be nice.
Not saying AV is the fix, but if Linux is ever going to become even slightly mainstream, you need some way to keep the “normies” from hurting themselves
No, av would not stop this kind of attack….
ClamAV is used widely though on inbound SFTP shares though in a corporate environment
